CN112062523A - A kind of thin spray material for reinforcement, beautification, support and sealing of coal mine roadway and preparation and use method thereof - Google Patents

Abstract

The invention discloses a thin spraying material for reinforcing, beautifying and supporting sealing of a coal mine tunnel and a preparation and use method thereof, wherein the thin spraying material is prepared from the following components in percentage by mass: 30 to 40 percent of Portland cement, 10 to 20 percent of fly ash, 10 to 20 percent of cast stone powder, 1 to 5 percent of kaolin, 0.01 to 1 percent of thickening agent, 0.01 to 0.5 percent of redispersible latex powder, 0.01 to 0.5 percent of water reducing agent, 0.5 to 8 percent of polyoxyethylene and the balance of water. When in use, the raw materials are prepared into slurry, and then the slurry is reproduced to be sprayed. The thin spray material has the advantages of excellent hydration film-forming property, tensile strength and bonding strength, low cost, quick curing, no rebound, no spontaneous combustion, smooth surface, safety and reliability.

Description

A kind of thin spray material for reinforcement, beautification, support and sealing of coal mine roadway and its preparation and application Instructions

technical field

The invention relates to the technical field of reinforcement and support of coal mine roadways, in particular to a thin spray material used for reinforcement, beautification, support and sealing of coal mine roadways, and a preparation and use method thereof.

Background technique

In recent years, my country's national economy has continued to develop rapidly, and the rapid development of electric power, metallurgy, building materials, chemicals and other industries has led to a substantial increase in the demand for coal, and consumption has increased year by year. my country's coal mines are mainly underground mining, which requires a large number of tunnels to be excavated underground. Most of the tunnel strata are sandstone shale, etc., which are unstable and easy to weather. Therefore, the use of roadway support to keep the roadway smooth and the surrounding rock stable is of great significance to coal mine construction and production. The basic purpose of supporting the roadway is to ease and reduce the movement of the surrounding rock, so that the cross-section of the roadway will not be excessively reduced, and at the same time prevent the scattered and damaged surrounding rock from falling.

At present, the method of spraying concrete or mortar after anchor net support is used to achieve the effect of closed support, but the traditional concrete support technology has many shortcomings. The damp underground environment often causes the corrosion of the metal anchor net and the serious weathering of the surface of the concrete spray coating, which reduces the service life of the support layer and poses a serious threat to the safety of the roadway workers; the traditional concrete has insufficient cohesion and high rebound rate. , not only causes a lot of loss of raw materials, but also is not good for the health of spraying operators, and the slurry is uneven, the surface is rough after spraying and curing, and the effect of beautifying the roadway cannot be achieved. It is difficult for the concrete sprayed layer to synchronize with the rock deformation, which causes the sprayed layer to fall off.

In recent years, researchers have observed the effect of bolt and shotcrete support, and proposed that the concrete shotcrete layer does not play a major bearing role. Therefore, the present invention proposes a new type of thin spraying material for mining, which not only overcomes the shortcomings of traditional shotcrete such as high rebound rate, large dosage, and low cohesion, but also pays more attention to the functions of roadway sealing and beautification.

SUMMARY OF THE INVENTION

One of the objectives of the present invention is to provide a thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which has a smooth and beautiful surface, good bonding performance, good sealing performance and good water resistance, and is suitable for underground wet environment operations.

The second purpose of the present invention is to provide the above-mentioned preparation method of the thin spray material for reinforcement, beautification, support and sealing of coal mine roadway, and the process is simple.

The third purpose of the present invention is to provide a method for using thin spray materials for reinforcement, beautification, support and sealing of coal mine roadways, which is easy to construct.

In order to achieve the above object, the technical scheme adopted in the present invention is as follows: a thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 30% to 40% Portland cement, 10% %～20% fly ash, 10%～20% cast stone powder, 1%～5% kaolin, 0.01%～1% thickener, 0.01%～0.5% dispersible polymer powder, 0.01%～0.5% water reducing agent, 0.5% to 8% polyethylene oxide, and the balance is water.

Preferably, the thin spray material for reinforcement, beautification, support and sealing of coal mine roadways is made of the following components by mass percentage: 30% Portland cement, 10% fly ash, 10% cast stone powder, 1% kaolin, 0.01% thickener, 0.5% redispersible latex powder, 0.01% water reducing agent, 1% polyethylene oxide, and the balance is water.

Preferably, the Portland cement is one of P.O.42.5, P.O.52.5, and P.O.62.5 ordinary Portland cement.

Preferably, the fly ash is 320 mesh secondary fly ash, which has the functions of reducing the cost of the thin spray material, reducing the hydration heat of the cement, and improving the later strength of the thin spray material through the pozzolan effect.

Preferably, the thickener is glycerol, which has good compatibility in water, is easy to adjust the viscosity of the slurry, and acts as a water-retaining agent and retarder for cement mortar to make the mortar pumpable, improve the spreadability and prolong the durability. operating time.

Preferably, the redispersible latex powder is ethylene-vinyl acetate copolymer (EVA) rubber powder, which has no adverse effect on the thixotropy and water retention of the slurry, and effectively improves the plasticity and adhesion of the slurry.

Preferably, the water-reducing agent is a naphthalene-based water-reducing agent, which has a super-dispersed type, can prevent the loss of concrete slump without causing obvious retardation, and exert a high plasticizing effect at a low dosage.

The present invention also provides the above-mentioned preparation method of the thin spray material for reinforcement, beautification, support and sealing of coal mine roadway, and the specific steps are as follows:

(1) Weigh the polyethylene oxide powder according to the proportion and add a certain amount of water, and stir for 2 to 4 hours in a water bath at 0 to 35° C. to dissolve it completely to obtain a polyethylene oxide solution;

(2) Weigh Portland cement, fly ash, cast stone powder, kaolin, thickener, water reducing agent, and redispersible latex powder according to the proportions, and add a certain amount of water after stirring evenly, and the temperature is 1200-1500r/min. Stir for 5 to 10 minutes at the rotating speed to obtain a mixed slurry for use;

(3) adding the polyethylene oxide solution obtained in step (1) to the mixed slurry obtained in step (2), adding a certain amount of water, stirring at a rotational speed of 1500-2000 r/min for 2-5 minutes, and ultrasonicating for 5-10 minutes , to obtain a thin spray material.

The present invention also provides the above-mentioned method for using the thin spray material used for reinforcement, beautification, support and sealing of coal mine roadways. The specific steps are: putting the pre-mixed thin spray material into the hopper of the spray machine; before spraying, pre-cleaning the job site , Remove obstacles on the working surface, clean up pumice, slag deposits, etc., and pre-embed the signs to control the thickness of the sprayed thin spray material slurry; select the appropriate wind pressure and spray distance to ensure uniform spraying of the slurry.

Compared with the prior art, the thin shotcrete material of the present invention overcomes the shortcomings of the traditional shotcrete material system, such as low efficiency, high energy consumption, serious pollution, etc., and can achieve rapid construction while achieving the traditional shotcrete effect, and has low dust and rebound. The rate is small, the amount of green environmental protection materials is small, the bonding strength and tensile strength are high, the surface is smooth and delicate, and it is not easy to crack, which can effectively prevent the weathering of surrounding rocks, support and beautify the roadway. At the same time, the thin spray material has the advantages of low construction cost, fast construction speed, low material consumption, cost saving, good economic benefit and huge application prospect.

Description of drawings

Fig. 1 is the SEM image of the thin spray material obtained in Example 1 of the present invention after curing;

FIG. 2 is a drawing curve diagram of the thin sprayed materials prepared in Examples 1-9 of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

In the following examples, the raw materials used without specifying the manufacturer are conventional products that can be purchased from the market.

The raw materials used in the following examples all meet the following requirements: the fly ash is 320 mesh secondary fly ash, the fineness of the cast stone powder is 200-400 mesh, the fineness of the kaolin is 1000-3000 mesh, The glass transition temperature of the ethylene-vinyl acetate copolymer rubber powder is -7°C to +12°C, the water reducing rate of the naphthalene-based water reducing agent is not less than 14%, and the relative molecular weight of the polyethylene oxide is Between 600,000 and 3,000,000, the water is tap water or drinking water, which meets the requirements of the "Concrete Water Standard" (JGJ63-2006).

Example 1

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 30% P.O.42.5 ordinary Portland cement, 10% secondary fly ash, 10% cast stone powder, 1 % kaolin, 0.01% glycerol, 0.5% ethylene-vinyl acetate copolymer rubber powder, 0.01% naphthalene water reducing agent, 1% polyethylene oxide, and the balance is water.

The specific preparation steps are as follows:

Step 1: Weigh a certain quality of polyethylene oxide powder according to the proportion, add it into a reaction vessel containing a certain amount of water, stir in a water bath at 0 to 85 ° C for 2 to 4 hours, and stir evenly to form a polyethylene oxide solution;

Step 2: Weigh Portland cement, fly ash, cast stone powder, kaolin, glycerol, naphthalene-based water reducing agent, and ethylene-vinyl acetate copolymer rubber powder according to the proportions, stir evenly, and add a certain amount of water. Stir at 1200-1500r/min speed for 5-10min to obtain mixed slurry;

In step 3, the polyethylene oxide slurry in step 1 is added to the above mixed slurry, stirred at 1500-2000 r/min for 2-5 min, and sonicated for 5-10 min to obtain a thin spray material.

The material prepared in this example was cured and observed under a scanning electron microscope (SEM), which showed that the surfaces of the materials were adhered to each other, forming a dense sheet-like whole, and the polymer material penetrated between the inorganic materials. Therefore, the overall bonding performance of the material is better.

Example 2

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 40% P.O.42.5 ordinary Portland cement, 10% secondary fly ash, 10% cast stone powder, 1 % kaolin, 0.02% glycerol, 0.3% ethylene-vinyl acetate copolymer rubber powder, 0.03% naphthalene water reducing agent, 2% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 3

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 40% P.O.42.5 ordinary Portland cement, 10% secondary fly ash, 15% cast stone powder, 1 % kaolin, 0.03% glycerol, 0.1% ethylene-vinyl acetate copolymer rubber powder, 0.05% naphthalene water reducing agent, 3% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 4

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 40% P.O52.5 ordinary Portland cement, 10% secondary fly ash, 15% cast iron Stone powder, 1% kaolin, 0.04% glycerol, 0.09% ethylene-vinyl acetate copolymer rubber powder, 0.07% naphthalene water reducing agent, 4% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 5

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 40% P.O.52.5 ordinary Portland cement, 10% secondary fly ash, 15% cast stone powder, 1 % kaolin, 0.05% glycerol, 0.07% ethylene-vinyl acetate copolymer rubber powder, 0.09% naphthalene water reducing agent, 5% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 6

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 30% P.O.52.5 ordinary Portland cement, 10% secondary fly ash, 20% cast stone powder, 2 % kaolin, 0.06% glycerol, 0.05% ethylene-vinyl acetate copolymer rubber powder, 0.1% naphthalene water reducing agent, 6% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 7

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 35% P.O.62.5 ordinary Portland cement, 15% secondary fly ash, 20% cast stone powder, 3% % kaolin, 0.07% glycerol, 0.03% ethylene-vinyl acetate copolymer rubber powder, 0.3% naphthalene water reducing agent, 7% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 8

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 35% P.O.62.5 ordinary Portland cement, 20% secondary fly ash, 20% cast stone powder, 4% % kaolin, 0.08% glycerol, 0.01% ethylene-vinyl acetate copolymer rubber powder, 0.5% naphthalene water reducing agent, 8% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

Example 9

A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways, which is made of the following components by mass percentage: 35% P.O.62.5 ordinary Portland cement, 20% secondary fly ash, 20% cast stone powder, 5% % kaolin, 1.0% glycerol, 0.01% ethylene-vinyl acetate copolymer rubber powder, 0.5% naphthalene water reducing agent, 0.5% polyethylene oxide, and the balance is water.

The preparation method is the same as that in Example 1.

In the formula, Portland cement is used as the main cementitious material, and after hydration, it gives the main tensile strength and compressive strength to the thin spray material.

Kaolin, cast stone powder and fly ash are used as inorganic fillers, which improves the bonding strength and tensile strength of the thin spray material, and its tiny particles are filled in the voids of the slurry, which effectively reduces the porosity of the thin spray material. rate, improve the compactness of the material, and reduce the cost at the same time. In addition, fly ash reduces the hydration heat of cement and improves the later strength of thin spray materials through the pozzolanic effect.

Glycerol, as a thickener, has good compatibility in water and is easy to adjust the viscosity of the slurry. And as a water-retaining agent and retarder for cement mortar, it makes the mortar pumpable, improves the spreadability and prolongs the operation time.

As a redispersible latex powder, ethylene-vinyl acetate copolymer rubber powder has no adverse effect on the thixotropy and water retention of the slurry, and effectively improves the plasticity and adhesion of the slurry.

As a water reducing agent, naphthalene-based water-reducing agent has a super-dispersed type, which can prevent the loss of concrete slump without causing obvious retardation, and has a high plasticizing effect at low dosage.

As a film-forming agent, polyethylene oxide has excellent film-forming properties, colloid protection and cohesiveness. After the slurry is cured, the surface is smooth and not easy to crack and has good construction performance. Forms a ductile-brittle cross frame structure with hydraulic materials to improve the deformability of thin sprayed materials.

Comparative Example 1

A thin spray material made of the following components by mass percentage: 30% P.O.42.5 ordinary Portland cement, 20% cast stone powder, 1% kaolin, 0.01% glycerol, 0.5% ethylene-vinyl acetate copolymer glue powder, 0.01% naphthalene-based water reducing agent, 1% polyethylene oxide, and the balance is water. The preparation method is the same as that in Example 1.

Comparative Example 2

A thin spray material made of the following components by mass percentage: 30% P.O.42.5 ordinary Portland cement, 20% fly ash, 1% kaolin, 0.01% glycerol, 0.5% ethylene-vinyl acetate copolymer Rubber powder, 0.01% naphthalene water reducing agent, 1% polyethylene oxide, and the balance is water. The preparation method is the same as that in Example 1.

The thin spray materials prepared in Examples 1 to 9 were respectively tested for tensile bond strength, and the tensile bond strength was measured according to the national standard GB/T25181-2010 "Ready-Mixed Mortar". The test results are shown in Table 1:

Table 1 Bond Strength Test

It can be seen from Table 1 that the bonding strength of the material on the concrete base is 2.81-4.35MPa, indicating that the material prepared by the present invention has high bonding performance with the base, which is beneficial to spraying and is not easy to fall off. In addition, from the comparison of Comparative Example 1, Comparative Example 2 and Example 1, it can be seen that the cohesive strength of the thin spray material prepared by adding fly ash or cast stone powder alone is low, while when fly ash, cast stone powder are added When stone powder and kaolin are compounded, the obtained thin spray material has the highest bond strength, indicating that kaolin, cast stone powder and fly ash are compounded as inorganic fillers, which improves the bond strength of the thin spray material.

Tensile strength tests were performed on the thin sprayed materials prepared in Examples 1 to 9, respectively. The tensile strength was tested according to the standard ASTMD638-2014 "Test Method for Tensile Properties of Plastics". The test results are shown in Figure 2. It can be seen from the tensile curve of the material that the material undergoes plastic deformation and has toughness, which is similar to the deformation curve of rock, which is beneficial to resist the deformation caused by external force.

The water resistance test was carried out to the thin spray materials prepared in Examples 1 to 9, respectively, and the steps were: under normal temperature and pressure, the thin spray materials prepared in Examples 1 to 9 were respectively made into sample strips and put into a beaker containing water. Soak for 48h. After the splines were put into water for 48h, they were neither dispersed nor dissolved in water, and the integrity of the splines was well maintained. It shows that the thin spray material prepared by the present invention is water-resistant and suitable for the application in the underground wet environment.

When the thin spray material of the present invention is used in the mine, the prepared thin spray material is put into the open silo of the spray machine in combination with the slurry sprayer. The machine applies the mixed spray material to a specific area of the site.

Before using spraying materials, first clean up the work site, remove obstacles on the working surface, remove pumice on the excavation surface, slag and deposits in the corners; pre-embed signs to control the thickness of the sprayed thin spray material slurry; select the appropriate wind pressure and spray distance to make the material spray evenly.

In order to achieve a better effect and make the coating structure more stable, after each layer of spraying is completed, the interval is 1-2d, and the second re-spraying is performed after the original sprayed layer is completely dried.

The thickness of the thin sprayed material is 3-20mm, the surface is smooth and delicate, and it has more beautifying effect than traditional sprayed concrete.

Of course, the above descriptions are only the preferred embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments. , and obvious deformation forms, all fall within the essential scope of this specification, and should be protected by the present invention.

Claims (9)

1. A thin spray material used for reinforcement, beautification, support and sealing of coal mine roadway, is characterized in that, it is made of the following components by mass percentage: 30%～40% Portland cement, 10%～20% fly ash , 10%～20% cast stone powder, 1%～5% kaolin, 0.01%～1% thickener, 0.01%～0.5% redispersible latex powder, 0.01%～0.5% water reducing agent, 0.5%～8% polyethylene oxide, the balance being water. 2. A thin spray material for reinforcement, beautification, support and sealing of coal mine roadway according to claim 1, characterized in that, it is made of the following components by mass percentage: 30% Portland cement, 10% pulverized coal Ash, 10% cast stone powder, 1% kaolin, 0.01% thickener, 0.5% dispersible polymer powder, 0.01% water reducer, 1% polyethylene oxide, and the balance is water. 3. A kind of thin spray material for coal mine roadway reinforcement, beautification, support and sealing according to claim 1 or 2, wherein the Portland cement is P.O.42.5, P.O.52.5, P.O.62.5 ordinary silicate A type of cement. 4. A thin spray material for reinforcement, beautification, support and sealing of coal mine roadways according to claim 1 or 2, wherein the fly ash is 320 mesh secondary fly ash. 5. A kind of thin spray material for reinforcement, beautification, support and sealing of coal mine roadway according to claim 1 or 2, characterized in that, the thickener is glycerol. 6 . The thin spray material for reinforcement, beautification, support and sealing of coal mine tunnels according to claim 1 or 2, wherein the redispersible latex powder is ethylene-vinyl acetate copolymer rubber powder. 7. A thin spray material for reinforcement, beautification, support and sealing of coal mine tunnels according to claim 1 or 2, wherein the water reducing agent is a naphthalene water reducing agent. 8. the preparation method of the thin spray material that is used for coal mine roadway reinforcement, beautification, support and sealing according to any one of claims 1 to 7, is characterized in that, concrete steps are as follows: (1) Weigh the polyethylene oxide powder according to the proportion and add a certain amount of water, and stir for 2 to 4 hours in a water bath at 0 to 35°C to dissolve it completely to obtain a polyethylene oxide solution; (2) Weigh Portland cement, fly ash, cast stone powder, kaolin, thickener, water reducer, and redispersible latex powder according to the proportions, and add a certain amount of water after stirring evenly, and the temperature is 1200-1500r/min. Stir for 5 to 10 minutes at the rotating speed to obtain a mixed slurry for use; (3) adding the polyethylene oxide solution obtained in step (1) to the mixed slurry obtained in step (2), adding a certain amount of water, stirring at a rotational speed of 1500-2000 r/min for 2-5 minutes, and ultrasonicating for 5-10 minutes , to obtain a thin spray material. 9. A method of using the thin spray material for reinforcement, beautification, support and sealing of coal mine tunnels according to any one of claims 1 to 7, wherein the concrete steps are: throwing the pre-mixed thin spray material into spraying Machine silo; before spraying, clean up the job site in advance, remove obstacles on the working surface, clean up pumice, rock slag, and deposits, and pre-embed signs to control the thickness of the sprayed thin spray material slurry; select the appropriate wind pressure and spray distance to ensure that the slurry is sprayed evenly.

Images